Another approach is to use Sturges' rule: use a bin so large that there are about 1+log2⁡n{\displaystyle \scriptstyle 1+\log _{2}n} non-empty bins (Scott, 2009).[2] This works well for n under 200, but was found to be inaccurate for large n.[3]
For a discussion and an alternative approach, see Birgé and Rozenholc.[4]